The present invention relates generally to the field of bioactive materials derived from animal blood platelet products, and methods of preparation and use thereof.
The administration of cells or compositions containing cells for therapeutic treatment is becoming an increasingly popular treatment modality. Such treatments may include, for example, the administration of mesenchymal stem cells (MSCs) which have the potential to differentiate into mesenchymal lineage cells including, for instance, bone, fat, cartilage, and muscle.
In order to obtain therapeutic amounts of cells for transplant it is often necessary to expand a population of cells from an initial population. The culture media used to expand the cell population supplies essential nutrients for cell metabolism, growth, and proliferation. Fetal Bovine Serum (FBS) is often used as a supplement to encourage population expansion. FBS has been a preferred supplement due to its low level of antibodies, because it contains many growth factors which stimulate cell growth and proliferation, and because it is relatively inexpensive to manufacture. However, FBS has recognized disadvantages including the risk of transmission of pathogens such as bovine spongiform encephalopathy.
Human platelet lysate (hPL) has emerged as a potential non-xenogenic alternative to FBS. hPL is derived from platelets known to contain a variety of growth factors. In addition to growth factors, current hPL isolation techniques commonly result in compositions which retain a high concentration of fibrinogen, a glycoprotein involved in clot formation. Because of their fibrinogen content and tendency to clot, current commercial hPL compositions are often used in conjunction with one or more anticoagulant additives, typically heparin. Anticoagulant additives in hPL increase the cost of hPL production and/or use and may be problematic in situations where the bioactivity of heparin is detrimental. Also, while a variety of processes for producing hPL have been proposed, attempts to achieve target compositional profiles or bioactivities for the hPL product have often led to process complexity and/or intensive equipment requirements. Significant adoption of hPL as a substitute for FBS will require economically practicable processes which nonetheless yield desirable and effective compositions.
In view of this background, needs exist for human platelet lysate compositions which are substantially free from fibrinogen, that retain growth factors beneficial to cell proliferation, and that can be readily and economically manufactured.